An .ini file is a simple text file used for configuration settings in software applications. It typically contains key-value pairs organized into sections, making it easy for programs to read and modify settings. The format is straightforward, allowing users to edit the file with any text editor. These files are commonly found in various operating systems, including Windows, where they help manage application preferences. While less common today due to more advanced configuration methods, .ini files remain a useful way to store settings for many legacy applications and games.